Gate construction for motion picture machines



0. WITTEL April 9, 1935.

GATE CONSTRUCTION FOR MOTION PICTURE MACHINES Filed Feb. 19, 1931Patented Apr. 9, 1935 PATENT OFFICE GATE CONSTRUCTION FOR MOTION PICTUREMACHINES Otto Wittel, Rochester, N. Y., assignor to Eastman KodakCompany, Rochester, N. Y., a corporation of New York ApplicationFebruary 19, 1931, Serial No. 516,849

15 Claims.

The present invention relates to a gate construction for motion picturemachines and more particularly to a gate construction for motion picturemachines using film having laterally displaced rows of imagesprogressive in opposite directions.

It has previously been proposed to close off the laterally adjacentunused row of images by means of a laterally sliding member magneticallyactuated. It has also been suggested that light leakage to or throughthe adjacent frame may be greatly reduced or eliminated by staggeringthe apertures in the presser pad. Staggering said apertures in thepresser pad requires two definite positions thereof corresponding to thedirection of movement of the film. This movement of the presser pad tothe desired positions has heretofore been accomplished manually orautomatically through additional mechanical means.

The primary object of the present invention is the provision of a gateconstruction, the presser means of which is moved into proper positionby frictional engagement with the film.

A further object of the invention is the pro vision of a stop means forlimiting the movement of said presser means between two extremepositions.

Another object of the invention is the provision of a framing meanswhich is operative in either of the extreme positions of the pressermeans to adjust the registry of one of the apertures therein with theimages on the film.

A still further object of the invention is the provision of a resilientlever means which movably engages the presser means to hold the same infrictional engagement with the film.

Still another object of the invention is the provision of blackened fiatgrooves in the presser means to give sharp edges to the aperturestherein and prevent the reflection of extraneous light from the pressermeans.

Other objects of the invention will be suggested by the followingdescription to those skilled in the motion picture art.

The specific and other objects of the invention are embodied in amachine having a guideway provided with an exposure aperture, means formoving film longitudinally past said aperture and a presser meansholding the film in the guideway, frictionally engaging and moved bysaid film. Stop means and framing means limit the movement of saidpresser means and permit adjustment of the presser pad in extremepositions respectively.

An embodiment of the invention is illustrated in the accompanyingdrawing wherein like elements are designated by the same referencenumerals, and wherein:

Figure 1 is a side elevation of a motion picture projector showing thepresser means in one extreme position.

Figure 2 is a perspective view of the guideway, presser means, film andresilient lever member, and

Figure 3 is a transverse cross-section of the guideway, film and pressermeans.

The improved gate construction of the present invention is shown asapplied to a motion picture projector, but it is to be understood thatthe gate construction may also be-applied to motion picture cameras orother apparatus without exceeding the scope of the invention.

In the illustrated embodiment a vertical longitudinal partition I isattached to a base H by means of bolts l2. A front plate 13 is mountedperpendicularly to partition IE] and base H and supports an objectivemount M. The objective lens barrel [5 is threaded into mount l4, and hasa knurled collar IE to facilitate rotation of barrel l5 to focus theobjective lens.

The light from lamp house I! passes through hole I 8 in partition 10onto mirror l9 from whence the light is reflected through the objectivelens barrel l5.

Film reels 20 and 22 are detachably mounted, respectively, on shafts 2|and 23 which are rotatably mounted in vertical longitudinal partition[0.

A sprocket wheel 24 is rotatably mounted in partition I0 and may beturned manually by a crank arm 25 and handle 26, or may be power driven,in opposite directions in known manner. A plurality of idle rollers 21are also rotatably mounted in partition l0 near sprocket wheel 24 inorder to properly maintain the film 28 against said sprocket wheel 24.

A pull down mechanism comprises intermeshing gears 29 and 30, a claw arm3| eccentrically mounted at one end on gear 29, intermediately hinged toone end of a lever arm 33 and having a claw 32 adapted to engage theperforations 34 of film 28. The other end of lever arm 33 iseccentrically mounted upon the end of a drum 35 integral with gear 30and a system of gears not shown, but of known construction,interconnects sprocket wheel 25 and gears 29 and 30.

A guideway 36 having an accurate front portion is attached to partitionID to surround the pull down mechanism, has shoulders 31, see Fig. 3,

advancing mechanism is deemed to be within the I scope of the expressionmeans for moving a film longitudinally in either of opposite directionspast said exposure aperture which is used in the claims.

The previously described or equivalent elementsior all types of motionpicture apparatus are well known and per se form no part of the presentinvention. 1 Y

A presser means such as a presser pad 39 has a longitudinally curvedform with reversely curved ends, has runnersllil making surface contactwith the perforated sidesof film 28 and is provided with a slot t lthroughwhich the claw 32 may move to engage film perforations 3 3. Thepresser means is provided with aplurality of transversely andlongitudinally displaced flat grooves 42 and 33, while aperturesii and45. are located in the middle of the fiat grooves and 553.,respectively. The thin edges of the apertures i -l and Q5 and the flatgrooves 32 and ii-i are covered with lamp black lacquer or blackened inany suitable manner to prevent the reflection of light from thesesurfaces into the objective. A central longitudinal rib it extendsaround the guideway, and across exposure aperture 38 while a secondcentral longitudinal rib ll is in-, tegral with presser padte. The ribsat and M are directly opposite each other and make contact with thecenter line of the film 23..

The presser means is resiliently held against the film by a resilientlever means so. that runners it as well as rib. 45?. make surfacecontact with the film 28 to provide frictional engagement between thefilm and presser. means. The other side of film 28 also. makes surfacecontact with runners 48 and rib 45 so that the film is guided throughand'maintained in proper position between guideway tfiiand presser pad39.

.The aforementioned resilient lever 'means is in movable engagement withsaidpresser means and may comprise an arm 59 pivoted to partition it bya bolt 51 a roller 5!. rotatably mounted on the :free. end: of arm 3-9.anda coil spring 52 encircling the hub of arm d9 with one end engaging astud 53 and the. other end engaging one edge of arm '69. Thus. theresilient means. holds the presser means resiliently against the film 28and the presser means movesin the same direction asthefilm by virtue ofthe frictional engagement therebetween. v 1

The. longitudinal movement of the pressermeans is limited by stop means{such as a pair of pins as positioned on guideway. 36. andprotruding'through slots 55 near one edge of presser pad 59,; The pins5% are so located and the slots. 55 of such a length, that the presserpad 39 is halted in its movement with the. film .either .with. aperturei l opposite one side of exposure aper-. ture 33,01 with aperture 45,opposite the other side of exposure aperture The positionof the. presserpad-when the film is traveling up. is shown in full lines inFig. Iwhile. the position of: presserpad 33. when the film is traveling; downis shown-in Fig. 2. 1

- The two extreme positions. in which-the stop -,diameters of pins meanslocate the presser means may not be such that the apertures 45 or i5therein are in exact registry with the corresponding images on the filmhence it is best to provide a framing means engaging said presser meansand permitting slight Variations in said extreme positions so that theimages of the film will be properly framed witheither ofsaid aperturesM. and 4 5. A suitable'framing' means may consist of a" bell crank 56pivotally mounted on partition ill by means of a bolt 5! so that one endof the bell crank 55 will move within or abut the ends of a slot 58 nearthe edge of presser pad 39. In order, that the framing means will beoperative in both extreme positions of the presser means, the slot 58 inpresser pad 39 is shorter than slots 55 and the width of hell crank 56is greater than the Thus in either extreme position of the presser meansthe framing means may be operative to move the presser means, and if, inone extreme position, of presser pad 35 the pins. 5.5. abut the correponding ends of lots 55., upon movement to. the other extreme positionthe bell crank 5.5, will abut. one end of. slot, 55 to stop the movementof pIcSserpad so before pins 54 abut the other ends of slots 55. v

The. p i n the. improved ate constructionis asfollows: V a 7 After thefilm is threaded through the motion picture apparatus, the. sprocketwheel is, hand or power driven to move the film loop around the guidewayvThe sprocket wheel 2,4 also drives the pull down mechanism through asystem of gears of well known design, said pull down imparting anintermittent movement to. the film in the loop. ,If the film'in theloop, moving in a clockwise direction the frictional engages mentbetween the presser means, and the film will move the presser means to,abut, the stop means or framing means in extreme downward positionillustrated in Fig. .2 in w ich position aperture (i5 of, the pressermeans is opposite one side oi exposure aperture 33.8.v If the aperture55 does not properly frame. the images on the right side of film 3.4%then the. framing means may be, operated. to move. the presser meansinto proper registry with said images.

At the end of the run or at any desiredtime the. direction of filmmovement may be reversed so.- that the film in the loop. moves. counterclockwise directionancl theirictional engagement between the, filmandpressermeans. will cause the. same. to. move to. the upper extremeposition, shown, in Fig; 1, abutting either the stop means. or framingmeans. Again it maybe nec-. essary to adjust the. presser means by,-operat.. ing the framing means so. that the. images on the leftside offilm 3e are properly framed within aperture 4.4; in the presser-means.

Fhe resilient, means is; operative. at all .times to hold the pressermeans. against the film but to also allow the presser means to. be movedby the irictionalcontact with the film. The use, of'

tion, what I claim as new and desire to secure by Letters Patent of theUnited States is:

1. A motion picture machine comprising a guideway provided with anexposure aperture, an advancing means adapted to move a film in eitherof opposite directions past said exposure aperture, a presser meansprovided with a plurality of displaced exposure apertures, a supportingmeans maintaining said presser means in frictional engagement with saidfilm, and for necessarily permitting said presser means to move ineither direction with said. film, and a stop means for limiting themovement of said presser means to locate one only of said displacedexposure apertures in registry with the first mentioned exposureaperture.

2. A motion picture machine comprising a guideway provided with anexposure aperture, an advancing means adapted to move a filmintermittently in either of opposite directions past said exposureaperture, a presser means provided with a pair of longitudinallydisplaced exposure apertures, a resilient member pressing said pressermeans against said film and for necessarily permitting said pressermeans to move in either direction with said film, and a stop means forlimiting the movement of said presser means to locate one only of saiddisplaced exposure apertures in registry with the first mentionedexposure aperture.

3. A motion picture machine comprising a guideway provided with anexposure aperture, an advancing means adapted to move a filmintermittently in either of opposite directions past said exposureaperture, a presser means provided with a pair of longitudinally andlaterally displaced exposure apertures, a supporting means solelysupporting said presser means in frictional engagement with said filmandfor necessarily permitting said presser means to move in eitherdirection with said film, and a stop means for limiting the movement ofsaid presser means with the film to locate one only of said displacedexposure apertures in registry with the first mentioned exposureaperture.

4. A motion picture machine comprising a guideway provided with anexposure aperture, an advancing means adapted to move a film in eitherof opposite directions past said exposure aperture, a presser meansprovided with an elongated slot and with a plurality of displacedexposure apertures, a supporting means supporting said presser means infrictional engagement with said film and for necessarily permitting saidpresser means to move in either direction with said film, and a pincooperating with said elongated slot to limit the movement of saidpresser means with the film and to locate one only of said displacedexposure apertures in registry with the first mentioned exposureaperture.

5. A motion picture machine comprising a guideway provided with anexposure aperture, an advancing means adapted to move a film havingimage frames in either of opposite directions past said exposureaperture, a presser means provided with a plurality of longitudinallydisplaced exposure apertures, a supporting means supporting said pressermeans in frictional engagement with said film and for necessarilypermitting said presser means to move in either direction with saidfilm, a stop means for limiting the movement with said film of saidpresser means between extreme positions and to locate one only of saiddisplaced exposure apertures in registry with the first mentionedexposure aperture and a framing means cooperating with said pressermeans for moving the same in either extreme position in a directionopposite to the film movement to locate one displaced exposure aperturein exact registry with the frames on said film. 5

6. A motion picture machine comprising a guideway provided with anexposure aperture, an advancing means adapted to move a film havingimage frames in either of opposite directions past said exposureaperture, a pressure means provided with an elongated slot and aplurality of laterally and longitudinally displaced exposure aperturesasupporting means supporting said presser means in frictional engagementwith said film and for necessarily permitting said presser means to movein either direction with said film;

a stop means for limiting the movement with said film of said pressermeans between extreme positions and to locate one only of said displacedexposure apertures in registry with the first mentioned exposureaperture, and a framing lever cooperating with the elongated slot insaid presser means for moving the same in either extreme position in adirection opposite to the film movement to locate one displaced exposureaperture in exact registry with the image frames on said film.

7. A motion picture machine comprising a guideway provided with anexposure aperture, an advancing means adapted to move a film hav- 3O ingimage frames in either of opposite directions past said exposureaperture, a presser pad provided with a pair of longitudinally extendingelongated slots of unequal length and with a pair of longitudinallydisplaced exposure apertures, a supporting means supporting said pressermeans in frictional engagement with said film and for necessarilypermitting said presser means to move in either direction with saidfilm,

a pin cooperating with the longer elongated slot to limit the movementwith said film of said presser means between two extreme positions and aframing lever cooperating with the shorter elongated slot to move thepresser means while in either extreme position in a direction opposite 5to the film movement to locate one of the displaced exposure aperturesin registry With the image frames on said film.

8. A motion picture machine comprising a guideway provided with anexposure aperture, an advancing means adapted to move a film in eitherof opposite directions past said exposure aperture, a presser padprovided with a pair of displaced exposure apertures, a resilient meansproviding the sole support for said presser pad and including a rollerwhich bears against said presser pad and which necessarily permits saidpresser pad to move in either direction with said film, and a stop meansfor limiting the movement with said film of said presser pad to locateone only of said displaced exposure apertures in registry with the firstmentioned exposure aperture.

9. A motion picture machine comprising a guideway provided with anexposure aperture, an advancing means adapted to move a film having 55image frames in either of opposite directions past said exposureaperture, a longitudinally curved presser pad provided with a pair ofdisplaced flat grooves and with displaced exposure apertures centrallylocated in respective grooves, a supporting means supporting saidpresser means in frictional engagement with said film and fornecessarily permitting said presser means to move in either directionwith said film, and a stop means for limiting the movement with the filmof said presser means to locate one on-lyof said displaced exposureapertures in registry with the, first mentioned exposure aperture.

' it). A motion picture machine comprising a guideway provided with anexposure aperture, an advancing means adapted to move a film havingimage frames in either of opposite directions past said exposureaperture, a longitudinally curved presser pad provided with a pair oflaterally and longitudinally displaced fiat grooves having blackenedsurfaces and with displaced exposure apertures centrally located inrespective grooves, a supporting means supporting saidpresser means infrictional engagement with said film and for necessarily permitting saidpresser means to move in either direction With said film, and a stopmeans for limiting the movement with said film of said presser means tolocate one only of said displaced exposure apertures in registry withthe first mentioned exposure aperture.

11. In a motion picture machine, the combination with a gate for guidinga film and including a presser member which is provided with anaperture, and an advancing means for moving said film in either ofopposite directions through said gate, of a means supporting saidpresser member in frictional engagement with said film and forpermitting limited movement of said presser member by the film and; inthe direction of film movement.

12. In a motion picture machine, the combie nation with a gate forguiding a film and including a presser member which is provided with anaperture for registering with areas on said film, and anadvancing meansfor moving said film in either of opposite directions through said gate,of a means supporting said presser member in frictional engagement withsaid film and with said aperture in a predetermined position and for permitting limited movement of said presser member by the film and in thedirection of film movement to move said aperture out of saidpredetermined'position.

13. A motion picture machine comprising an optical system, a gate forguiding a film and including a presser member which is provided with anexposure aperture in optical'relation to said optical system, anadvancing means for moving I said film in either oi opposite directions,through said gate, and a supporting means for maintaining said pressermember in frictional engagement an exposure aperture out of opticalrelation to' said optical system, an advancing means for moving saidfilm in either of opposite directions through said gate, and asupporting means for maintainingsaid presser member in frictionalengagement with said film, characterized by said supporting means alsopermitting limited movement of said presser member by the film and inthe direction of film movement to move said aperture into opticalrelation with said optical system upon reversal in the direction of saidfilm movement. I i

15. In a motion picture machine, the combination with a gate for guidinga film and including a presser member which is provided with anaperture, and an advancing means for moving said film in, either ofopposite directions through said gate, of a supporting means formaintaining said presser member in frictional engagement with said filmand for permitting movement. of said presser member by the film and inthe direction of film. movement,- and a. stop means for engaging saidpresser member and for limiting the movement thereof with said film.

OTTO WITTEL.

